Author(s): WANG, J., Institution: PEKING UNIVERSITY, Country: CHINA, Abstract-ID: 2076

INTRODUCTION:
Exercise as a non-pharmacological intervention has been widely recognized for its benefits on metabolic health. The effects of morning or afternoon exercise on different metabolic indicators are different, and this paper aims to systematically evaluate and analyze the effects of exercise at different times on body composition, glucose metabolism and lipid metabolism.
METHODS:
Following the PRISMA guidelines, this study conducted a literature search through electronic databases such as PubMed, Em base and Web of
Science. The included studies included exercise regimens in the morning, afternoon or morning and evening, and analyzed body weight, Body Mass Index, fat mass, fasting blood glucose, HbA1c, insulin, and triglycerides. The risk of bias was assessed using the Cochrane tool (Rob2), and publication bias was assessed by funnel plot and Egger test.
RESULTS:
13 long-term studies and 5 acute studies were analyzed(n=658 participants). Morning exercise (MT) was more effective in reducing body fat(MD-0.39, 95% CI [-0.66 to -0.13], I² = 0%, p = 0.004), waist circumference(MD-0.53, 95% CI[-1.06 to-0.00], I² = 31%, p = 0.05), and HbA1c(MD-0.11, 95% CI[-0.19 to -0.03], I² = 0%, p = 0.009), while afternoon exercise (AT) was better in lowering fasting blood glucose(MD 0.13, 95% CI [0.01 to 0.24], I² = 0%, p = 0.03) and triglycerides(MD 0.1, 95% CI [0.02 to 0.18], I² = 41%, p = 0.02).
CONCLUSION:
Both morning and afternoon exercise are beneficial to metabolic health, but the effects are different. Morning exercise was more likely to reduce body fat, waist circumference and HbA1c, while afternoon exercise was more likely to reduce fasting blood glucose and triglycerides.